Venoms of sea snakes, (Hydrophiidae), contain potent neurotoxins. As compared with land snakes, sea snakes and their venoms have not yet been extensively investigated. In order to understand the mode of action of sea snake venom toxins, we plan to isolate the toxins in highly purified form. Their chemical, physical, toxicologic, and pharmacologic properties will be investigated. We plan to investigate the relationship between conformation and toxic action by laser Raman spectroscopy. We also will investigate whether sea snake neurotoxin has actions other than neurotoxic actions. Finally, we would like to find ultrastructural evidence of neurotoxins localized in the post-synaptic membrane of the motor-end plate by an immunohistochemical technique. We hope that our research will contribute to the long-range objectives of chemotherapy for sea snake poisoning.